High-friction geo-textiles for increasing the stability of landfill drainage layers and other high-friction angle installations, and related methods

ABSTRACT

The present invention relates generally to geo-textiles having an increased resistance to the negative effects of shear forces in installations or layered structures which can be adapted and arranged to utilize geo-textiles. Geo-textiles of the invention comprise at least one high-friction compound, such as one or more high-friction polymers, and methods for making and utilizing them. The high-friction characteristics of components of the invention provide increased resistance to the negative effects of shear forces in layered installations which employ them. Geo-textiles of the invention may have one or more high-friction compounds provided on either or both surfaces. Geo-textiles according to the invention are particularly useful in sloped installations where at least a portion of the layered structure is at a slope angle of greater than 4 degrees, and can be interposed between one or more of geo-membranes, geo-grids, geo-cells, geocomposite laminates and conventional geo-textiles.

FIELD OF THE INVENTION

The present invention relates generally to woven and non-wovengeo-textiles which comprise high-friction components, such as polymers,on one or both of their surfaces, and methods for making and utilizingsuch high-friction geo-textiles. Geo-textiles of the invention provideincreased resistance to the negative effects of shear forces in layeredinstallations which employ them, such as those comprising geo-membranes,geo-nets, void-maintaining geo-composite core elements and other layeredgeo-composite structures. Moreover, the present invention provides meansand methods for decreasing the destructive effects of shear forces onlayered temporary covers used in landfills and the like.

The high-friction characteristics of the many embodiments of theinvention provide engineers and designers with the ability to design,plan and build installations having sloping portions of steeper anglesthan those achievable without the present invention. Thus, thegeo-textiles and methods of the present invention enable a significantincrease in the effective volume of installations such as landfills andartificial basins to collect drainage fluids and other effluent.Advantageously, this increases the efficiency of land usage, and theavailable storage capacity of landfills, storage basins and similarstructures.

BACKGROUND OF THE INVENTION

Water is the principal cause of distress in many types of structures.For this reason among others, geotechnical engineers and others skilledin the field of designing drainage systems for large structures oftenspecify sand, stone, piping manifolds, clay and gravel as a means ofproviding drainage layers and structures, such as collection pipe fieldsand sumps, to convey effluent away from the structure. More recently,layered structures of polymer or other synthetic materials have beenused to provide drainage capacity for large structures such aslandfills, highways, parking lots and runways. Such polymer materials,typically geo-membranes, geo-nets and geo-composites, are currently usedto complement or replace natural earthen materials such as stone, graveland clay. In another common function, geo-membranes and geo-textiles areemployed as permanent or temporary (“day”) covers for coveringlandfills.

In some applications, layered combinations of geo-membranes,geo-textiles, geo-nets and other synthetic planar or sheet-likestructures are provided in order to achieve desired drainage capacities.Typically, these layered structures are intended to retain the drainageor void spaces that exist in the geo-net core element, in part, byretaining the relative positions of the layers with respect to oneanother over time. By retaining the relative positions of the layers,the overall integrity of the layered installation is preserved, and thedrainage capacity is kept within desired specifications.

A typical problem with conventional geo-textiles, geo-composites,geo-nets, geo-grids and methods for their use are numerous. For example,in many applications, such as in landfills, the various layers aresubject to mechanical stresses such as horizontal shear forces.Typically, these shear forces occur approximately parallel to the planeof the layers in the installation, for example, between a geo-membranewhich lines the sloping sides of a landfill and the adjacent geo-grid,geo-composite or geo-textile layer. Such shear forces tend to disruptthe relative positions of the various layers thus causing a partial orcomplete failure of the drainage system because, for example, intrusionof the outer layers into the void spaces.

Such horizontal forces are increased in installations of significantslope, such as those sloping more than 3 degrees. There is thus a needin the field for geo-composites that are resistant to shear forces andparticularly for use in those installations having a slope of more than3 degrees. There is a similar need for means and methods which exhibitsuperior resistance to the shear forces typically present in layereddrainage installations.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide woven andnon-woven geo-textiles comprising high-friction compounds on one or bothsurfaces which provide an increased resistance to shear forces betweenthe geo-textiles and one or more adjacent surfaces, such as one or moreof geo-membranes, geo-nets and geo-grid.

It is another object of the invention to provide high-frictiongeo-textiles which are useful in layered structures and have superiorcharacteristics with respect to functional longevity, performance andinter-layer resistance to shear forces.

It is a similar object of the invention to provide methods formanufacturing such high-friction geo-textiles, and methods for usingthem in landfills and similar large structures.

In accordance with these and other objects, a geo-textile having a firstsurface and a second surface is provided, wherein the geo-textilefurther comprises at least one high-friction compound on at least aportion of the first surface, such that the geo-textile possesses anincreased resistance to shear forces when the geo-textile is in adjacentcontact with the surface of another layer, for example, in a landfill orother high slope angle installations. In accordance with thespecifications and context of use of a particular high-frictiongeo-textile of the invention, one or more high-friction compounds areprovided on at least part of the surface area of the first side of thegeo-textile, that is, on a first area portion of the first side of thegeo-textile.

Preferably, the one or more high-friction compounds are provided on afirst area portion of the first surface, and the first portion comprisesa percentage of the surface area of the first surface, for example, onat least 20% of the surface area of the first surface, or on at least45% of the surface area of the first surface, depending on theparticular high-friction angle, the type or types of high-frictioncompounds, the type and nature of the adjacent layers, and the pressuresand other conditions to which the geo-textile and adjacent layers willbe subjected. In other embodiments, the one or more high-frictioncompounds are provided on at least 70% of the surface area of the firstsurface, or at least 95% of the surface area of the first surface. Inaccordance with other advantages of the invention, the first side of thegeo-textile can be completely covered by one or more high-frictioncompounds, that is, the first area portion covered by the high-frictioncompound or compounds can be 100% of the surface area of the firstsurface of the geo-textile. In a like manner, the same compound orcompounds may be applied also to the second surface of the geo-textile.

In accordance with other significant aspects of the invention, the oneor more high-friction compounds can be any that satisfy the requirementsof a particular installation, such as, the degree of effectiveness ofthe frictional characteristics of the compound, the particularhigh-friction angle, the type or types of adjacent layers, theresistance to chemical degradation, and the pressures and otherconditions which the geo-textile will experience. Particular compoundswhich are especially useful as high-friction compounds of the inventioninclude silicone-based compounds, ethylene vinyl acetates (“EVA's”),styrene butadiene rubbers, polyesters, ABS, polybutylenes, recycledlatexes, recycled tire compounds, polyethylenes, polyvinyl acetates(“PVA's”), rubberized polyethylenes, ethylene propylene diene monomers,ethylene vinyl alcohol copolymers, polypropylenes, rubberizedpolypropylenes, polybutadienes, plasticized polyvinyl chlorides,thermoplastic olefms, silicone compounds, and compounds derived fromrecycled tires. Such compounds may similarly be used on the secondsurface of the geo-textile, or may be interwoven or interposed amongfibers of the geo-textile during manufacture.

Geo-textiles of the invention can be any of natural or synthetic fibersas long as they are adaptable to bond with the high-friction compound orcompounds of the invention, for example, woven or non-wovengeo-textiles, and needle-punched or non-needle-punched geo-textiles andgeo-mats. The geo-textile and high-friction compounds of the inventioncan be bonded or adhered to one another by any means or methods whichresult in application of the high-friction compound to the geo-textilesuch that the desired engineering parameters are achieved. For example,the high-friction compound or compounds can be adhered to the at leastone of the surfaces of the geo-textile by one or more of thermalbonding, by one or more adhesives, by laser welding, by hot-meltbonding, by ultrasound, and by the adhesive properties of thehigh-friction compound itself. Thus, the selection of the one or morehigh-friction compounds to be used on one or both surfaces of thegeo-textile may be made with respect to the aspect of the adhesiveproperties of the selected one or more high-friction compoundsthemselves.

Thermal bonding of the high-friction compound to the geo-textile can beaccomplished by any means or methods which result in a sufficient bondbetween the compound and the geo-textile. For example, thermal bondingcan be accomplished by effecting deposition of one or more of thehigh-friction compounds upon the first surface of the geo-textile, andthen supplying sufficient heat to one or more of the high-frictioncompound and the geo-textile such that the bonding is accomplished.Thermal bonding can be accomplished regardless of the form of the one ormore high-friction compounds to be bonded to the geo-textile. Forexample, the one or more high-friction compounds can be deposited in theform of one or more of strands, fibers, beads, globules, flakes,powders, pellets, gels, liquids, crystals, films, matrices and sheets,and then sufficient heat may be added to bond the high-friction compoundto the geo-textile.

As an additional advantage, the high-friction compound can be applied tothe geo-textile in one or more patterns, for example, straight rows,curved rows, straight stripes, curved stripes, intermittent squares,intermittent circles, intermittent eccentric shapes, regular polygons,irregular polygons, checkerboards, lattices, wave patterns and repeatingfree-form or miscellaneous designs. The high-friction compound can alsobe applied randomly as may be desired or advantageous. In anothersignificant aspect, geo-textiles of the invention may have one or morehigh-friction compounds on all or portions of both surfaces, therebyadding to the diverse circumstances in which geo-textiles of theinvention may be used.

Thus, a geo-textile of the invention may further comprise ahigh-friction compound provided on a second area portion of the secondsurface, wherein the second portion comprises a percentage of thesurface area of the second surface, for example, on at least 20% of thesurface area of the second surface, or on at least 45% of the surfacearea of the second surface, depending on the particular high-frictionangle, the type or types of high-friction compounds, the type and natureof the adjacent layers, and the pressures and other conditions to whichthe geo-textile and adjacent layers will be subjected. In otherembodiments, the one or more high-friction compounds are provided on atleast 70% of the surface area of the second surface, or at least 95% ofthe surface area of the second surface. In accordance with otheradvantages of the invention, the second side of the geo-textile can becompletely covered by one or more high-friction compounds, that is, thesecond area portion covered by the high-friction compound or compoundscan be 100% of the surface area of the second surface.

As yet an additional advantage, the one or more high-friction compoundsmay be interwoven among the fibers of the geo-textile during manufactureof the geo-textile such that the high-friction compound is disposed onat least a portion of the first surface or on at least a portion of bothfirst and second surfaces. The one or more high-friction compounds maybe provided in the form of fibers, strands or pellets which areinterposed or interwoven among the fibers of the geo-textile duringmanufacture of the geo-textile such that the high-friction compound isdisposed on at least portions of one or both of the first and the secondsurfaces.

Geo-textiles of the invention are suitable for a myriad of uses, andespecially those uses wherein the adjacent surface of another layer isone or more surfaces or layers from the group comprising geo-membranes,geo-grids, geo-textiles, paved surfaces, earthen surfaces,earth-aggregate surfaces, geo-nets, geo-mats and geo-cells.

As yet another advantage, the one or more high-friction compounds mayhave inherently adhesive properties, or those properties that can beactivated by one or more of the processes suitable for forming ormanufacturing geo-textiles of the invention. Thus, the one or morehigh-friction compounds may be selected for their adhesive propertiesand thus be suitable for adhering the geo-textile to another surface,for example, to one or more surfaces of a geo-net, a geo-membrane, ageo-cell, a void-maintaining core structure, and a second geo-textile.

Geo-textiles of the invention may be adapted and arranged such that thehigh-friction compound extends above the first or second surfaces of thegeo-textile to which it is bonded. Thus the high-friction compound mayhave a thickness above the surface of the geo-textile to which itapplied the thickness being measured perpendicularly from the averagemean surface of the geo-textile. Because the one or more high-frictioncompounds extend above the surface of the geo-textile, it providesadditional gripping ability, for example, when the geo-textile isadjacent another layer, such as a geo-net or geo-grid, which alsopossesses dimensional features which can interact with the raisedthickness of the high-friction compound. In some preferred embodiments,the thickness of the one or more high-friction compounds on the firstsurface of the geo-textile is preferably 0.1 millimeter, or at least 0.1millimeter. In other preferred embodiments the first thickness is atleast 1.0 millimeters, or at least 2.0 millimeters, or least 3.0milli-meters. In embodiments of the invention where geo-textiles haveone or more high-friction compounds on both surfaces, the compound onthe second surface has a second thickness, and the second thickness canbe of similar dimensions as those of the first surface, or can be ofdifferent dimensions. Moreover, the high-friction compound provided oneach of the two surfaces may be provided in different, or varying,thick-nesses, and in different patterns or dispositions.

In accordance with additional advantages of the invention, methods forforming geo-textiles having an increased resistance to horizontal shearforces with respect to one or more adjacent surfaces are provided. Inone preferred embodiment, a method of the invention comprises the stepsof A, providing a geo-textile, the geo-textile having a geo-textilefirst surface and a geo-textile second surface, and then B, effectingapplication of at least one high-friction compound to the geo-textilefirst surface. The at least one high-friction compound can be appliedto, or bonded to, the geo-textile in any way or by any means appropriateto joining the compound to the geo-textile sufficiently so that thedesired degree of functionality is achieved.

For example, application of the high-friction compound to thegeo-textile first surface may effected by first i) providing thehigh-friction compound onto the first surface as the geo-textile isbeing formed, and then ii) applying sufficient heat to one or more ofthe high-friction compound and the geo-textile such that thehigh-friction compound and the geo-textile are bonded to one another. Inanother preferred embodiment of methods of the invention, theapplication of the high-friction compound to the geo-textile firstsurface is effected by providing the high-friction compound onto thefirst surface after the geo-textile is formed, and then applyingsufficient heat to one or more of the high-friction compound and thegeo-textile such that the high-friction compound and the geo-textile arebonded to one another.

Heat sufficient to bond the high-friction compound to the geo-textilemay be provided by any combination of means and methods which result ina sufficiently bonded product. As examples, the heat may be provided byone or more of flames, heated air, steam, infrared radiation, heatedrollers, heated platens between which the geo-textile and high-frictioncompound are passed, microwaves, ultra-sound, the melt heat of thehigh-friction compound itself, the heat of formation of the geo-textileand the residual heat from the processing of either or both of thehigh-friction compound and of the geo-textile.

Application of the high-friction compound to the geo-textile firstsurface may be effected by any means or methods desired, for example, byone or more of spraying, random spattering, ultrasound, extrusion of thehigh-friction compound onto the first surface as the geo-textile isbeing formed, extrusion of the high-friction compound onto the firstsurface after the geo-textile is formed, laser melting of thehigh-friction compound onto the first surface, and hot-melting of thehigh-friction compound onto the first surface.

The at least one high-friction compound may be provided in any formappropriate to achieving the desired parameters of the final product,such as the proportion of surface area to be covered, the finalthickness, the final pattern and relative bond strength. Examples ofappropriate include, but are not limited to one or more of strands,fibers, beads, globules, flakes, powders, pellets, gels, liquids, films,matrices and sheets. High-friction compounds appropriate for the methodsof the invention are any that achieve the desired characteristics inbonding to the geo-textile and performance parameters, and include thoselisted above with respect to the high-friction geo-textile products.

In accordance with other aspects of the methods of the invention, thehigh-friction compound may be provided on at least a first area portionof the first surface, wherein the first area portion comprises apercentage of the surface area of the first surface. Preferably, the oneor more high-friction compounds are provided on the first area portionof the first surface, for example, on at least 20% of the surface areaof the first surface, or on at least 45% of the surface area of thefirst surface, depending on the particular high-friction angle, the typeor types of high-friction compounds, the type and nature of the adjacentlayers, and the pressures and other conditions to which the geo-textileand adjacent layers will be subjected.

In other preferred embodiments, the one or more high-friction compoundscan be provided on at least 70% of the surface area of the firstsurface, or on at least 95% of the surface area of the first surface. Inaccordance with still other advantages of the invention, the first sideof the geo-textile can be completely covered by one or morehigh-friction compounds, that is, the first area portion covered by thehigh-friction compound or compounds can be 100% of the surface area ofthe first surface of the geo-textile. In a like manner, the same orsimilar compound or compounds may be applied also to the second surfaceof the geo-textile.

Methods of the invention also offer the advantage of producinghigh-friction geo-textiles wherein the high-friction compound applied toeither or both surfaces may be provided in one or more desiredthicknesses, for example, the high-friction compound applied to thefirst surface may have at least one first thickness, the thickness beingmeasured perpendicularly from the average mean surface of thegeo-textile, wherein the first thickness is at least 0.1 millimeters. Insome preferred embodiments of methods according to the invention, thethickness on the first surface of the geo-textile, that is, the firstthickness of the high-friction compound, is preferably 0.1 millimeter,or at least 0.1 millimeter. In other preferred embodiments the firstthickness is at least 1.0 millimeters, or at least 2.0 millimeters, orleast 3.0 millimeters. In embodiments of the invention wheregeo-textiles have high-friction compound on both surfaces, the compoundon the second surface has a second thickness, and the second thicknesscan be of similar, or different, dimensions as those of thehigh-friction compound on the first surface.

High-friction geo-textiles of the invention can be used in numerousways. They are particularly suitable for increasing the stability oflandfills and in other high-friction angle installations. Thus, inaccordance with other advantageous aspects of the invention, methods forincreasing resistance to the undesirable effects of horizontal shearforces between one or more layers of geo-membranes, geo-textiles,geo-composites, geo-nets, geo-cells and void-maintaining layers in alandfill installation, are provided.

In one preferred embodiment, the method comprises the step of providinga sheet-like high-friction geo-textile, the geo-textile having a firstsurface and a second surface,wherein the geo-textile comprises meansdisposed on at least the first surface of the geo-textile for increasingthe coefficient of friction between the geo-textile and an adjacentlayer, and then the step of placing, or effecting the disposition of thehigh-friction geo-textile, adjacent to one or more of the geo-membranes,the geo-textiles, the geo-nets, the geo-cells, and the void-maintaininglayers.

Thus, a high-friction geo-textile of the invention may be utilized byplacing it, for example, between a geo-membrane and a geo-grid, betweentwo geo-membranes, between a geo-membrane and a second geo-textile,between a geo-membrane and a void-maintaining layer, between ageo-membrane and a geo-net, between two geo-textiles or between twogeo-nets. Geo-textiles of the invention can also be used to increase thefrictional forces, that is, the resistance to shear forces, between theearthen, stone or aggregate surfaces of a landfill or similar structure,and an adjacent layer such as one or more of a geo-membrane, a geo-grid,a geo-cel, a geo-net, a second geo-textile, and a void-maintaininglayer. In a like manner, the geo-textiles of the invention may be usedas part of, or among the layers of the one or more covers, for example,for landfill installations or for covering other large structures wherethe cover is at least partially on a slope. Thus, the disposition of ahigh-friction geo-textile of the invention may be on top of at least aportion of the landfill and underneath at least one of thegeo-membranes, the geo-textiles, the geo-nets and the void-maintaininglayers.

Methods of the invention include use of any high-friction textile ortextiles, such as those described herein. High-friction textiles for usewith the present methods include those wherein the means for increasingthe coefficient of friction between the geo-textile and an adjacentlayer comprises at least one high-friction compound selected from thosedescribed elsewhere herein, and bonded to the geo-textile. The presentmethods include also the use of geo-textiles comprising means on boththe first and the second surfaces of the geo-textile for increasing thecoefficient of friction between the geo-textile and the adjacent layers.The first and second surfaces of the geo-textiles may have some or allof their respective surfaces areas covered by the one or morehigh-friction compounds as is described herein with respect to thedisclosed high-friction geo-textiles. Moreover, the present methodsinclude wherein the high-friction compound on the subject geo-textileshas one or more thicknesses as described elsewhere herein. Inembodiments where the high-friction compound projects above the surfaceof the geo-textile, the mechanical engagement of the compound with theadjacent layer increases the resistance to shear forces even further.

DETAILED DESCRIPTION OF THE INVENTION

Geo-textiles of the invention may comprise any substance having acoefficient of friction sufficiently high enough, so that when it isincorporated into one of the present geo-textiles, and placed in aninstallation having a desired slope, the desired performancecharacteristics, longevity, and resistance to slope failure areachieved. The one or more high-friction compounds can be thus any thatsatisfy the requirements of a particular installation, such as, thedegree of effectiveness of the frictional characteristics of thecompound, the particular high-friction angle, the type or types ofadjacent layers, the resistance to chemical degradation, and thepressures and other conditions which the geo-textile will experience.

Particular compounds which are especially useful as high-frictioncompounds of the invention include silicone-based compounds, ethylenevinyl acetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS,polybutylenes, recycled latexes, recycled tire compounds, polyethylenes,polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylenepropylene diene monomers, ethylene vinyl alcohol copolymers,polypropylenes, rubberized polypropylenes, polybutadienes, plasticizedpolyvinyl chlorides, thermoplastic olefins, silicone compounds, andcompounds derived from recycled tires. Such compounds may similarly beused on the second surface of the geo-textile, or may be interwoven orinterposed among fibers of the geo-textile during manufacture.

The adhesion or bonding of the geo-textile to the high-friction compoundcan be effected by any means or methods that result in sufficientresistance to movement under shear forces, including one or more ofthermal bonding, such as flame welding, the simultaneous or serialapplication of one or more adhesives or solvents, laser welding andultrasound. As one of skill in the art will appreciate, such additionalbonding means increases further the degree of adhesion between thegeo-textile and the high-friction compound. As one of skill in thepolymer arts will also comprehend, in addition to the high-frictioncompounds iterated herein, there are numerous other polymers that have,or that can be treated or processed to have, high-frictioncharacteristics that are suitable for use as high-friction compounds ofthe present geo-textiles.

In numerous permutations and embodiments, the high-friction geo-textilesand methods of the invention are particularly useful in situations whereall or at least a portion of the layered installation is on a slope, forexample, a slope away from a large structure or one or more slopesleading to the lower levels of a waste landfill. Numerous variations andpermutation of methods and woven and non-woven geo-textiles of theinvention are particularly suitable for slopes in the range of from 1degree to 25 degrees, preferably from 4 degrees to 20 degrees, morepreferably from 4 degrees to 15 degrees and most preferably from 4degrees to 10 degrees.

The present invention utilizes one or more high-friction compounds toprovide numerous embodiments and combinations of high-frictiongeo-textiles, which yield the advantageous characteristics of highresistance to horizontal shear forces. The present invention relatesgenerally to means and methods for making and utilizing them but alsopertains to numerous specific combinations of high-friction compoundsand woven or non-woven geo-textiles. The high-friction characteristicsof components of the invention also provide increased resistance to thenegative effects of shear forces in laminates which employ them.Geo-textiles of the present invention exhibit superior strength withrespect to resisting the destructive effects of shear forces on thevoid-maintaining capacities of adjacent geo-nets or othervoid-maintaining layers, particularly in sloped installations. Becauseof this, geo-textiles of the present invention can be used, for example,to more effectively permit the design and formation of landfills havingsteeper than conventional and in similar sloped geotechnicalapplications.

By providing a synthetic drainage system or impermeable barrier thatincludes the heretofore unknown high-friction geo-textile components,the present geo-textile invention overcomes the disadvantages of layeredgeo-composite failure caused by displacement of the layers with respectto one another by the stresses caused by horizontal shear forces. Thegeo-textiles and geo-fabrics used in the present invention arepreferably manufactured with specified or defined permeability andperrnittivity properties in order to adapt or integrate them intodrainage systems that have effective useful lives. A high-permittivitycore element, such as the geo-net shown in U.S. Pat. No. 5,891,549 toBeretta et al., is exemplary of geo-nets suitable for use adjacent tothe high-friction geo-textiles of the present invention. Numerous othergeo-nets, geo-membranes, geo-cells, geo-grids, and void-maintaininglayers are also suitable for use in the invention.

Tire rubber compounds useful for practicing the present invention arethose that are known in the art of tire manufacturing and tirerecycling. Thus, a geo-textile of the invention may comprise one or morehigh-friction compounds derived from recycled tire rubber. Used tiresthat have been processed into usable elastomers, for example, by themethods disclosed in U.S. Pat. Nos. 5,114,648; 6,129,877 and 5,494,510,all to Kuc, Sr., are adaptable for use in the present invention. TheKuc, Sr. patents are hereby incorporated by reference.

High-friction compounds produced in whole or in part from the polymersand rubber used to make tires have high-friction characteristicsadaptable for use with the present geo-textiles. Pelletized tire chipsmarketed under the trademark Duroplas® are one source of re-formulatedtire rubber and tire polymer compounds suitable for application to wovenor non-woven geo-textiles along with other polymers according to thepresent invention. Other sources of such re-formulated tire materialsare also suitable for practicing the invention.

The present invention provides high-friction geo-textile elements thatcan be combined with one another or with one or more conventionalgeo-structures such as geo-nets, geo-membranes and geo-textiles, orcombinations of these, such as are typically found in geo-laminates, orin similar layered drainage structures. Such high-friction elementsincrease the layer-to-layer adhesion and resistance to horizontal shearbetween adjacent layers in a layered structure. Because of this,geo-structures incorporating the present invention, such asvoid-maintaining drainage layered structures, can be installed and usedat greater slope angles while increasing the resistance to failurecaused by shear forces thereby decreasing slope failure and the need foranchors in sloped installations.

The effectiveness of the present invention is demonstrated by itssuperiority of performance when compared with a conventionalgeo-textile, and particularly with respect to the performance ofconventional geo-textiles adjacent a smooth geo-membrane. In most uses,smooth geo-membranes are preferable to textured geo-membranes becausethey are less expensive and have superior mechanical properties.

The interface shear strength between a geo-textile of the presentinvention and a smooth HDPE geo-membrane is greatly enhanced. A testembodiment of the present invention utilizing EVA as the high-frictioncompound on one of its two surfaces was evaluated. The test embodiment,having one high-friction surface, was tested in accordance with ASTMD5321. ASTM D5321 is the standard direct shear test (2002) fordetermining the coefficient of friction between soil and an adjacentgeo-synthetic product, or between two adjacent geo-synthetic products.

The test embodiment, having a thickness of 2.0-3.0 mm, was tested inaccording with ASTM D5321 and under normal compressive loading typicalof a landfill capping system, that is, at pressures of 1, 2, and 4lb/in2. The test embodiment achieved a peak friction angle of 26.7degrees. This is in stark contrast with the typical 11.0 degree peakfriction angle of a conventional non-woven geo-textile when placedadjacent a smooth HDPE geo-membrane. With non-woven needle puncturedgeo-textiles of various weights, based on a database of 149 large scaledirect shear tests, with the square of the correlation coefficient beingat 0.93. In other words, the present invention increases the peakfriction angle of the test embodiment by 142%, an enormous increase.

Moreover, the large displacement, sometimes called the residual frictionangle, yields a value of 19.8 degrees for the test embodiment. This isin sharp contrast to the typical 9.0 degrees of a conventional non-wovengeo-textile when tested adjacent a smooth HDPE geo-membrane, and withnon-woven needle punctured geo-textiles of various weights, based on adatabase of 82 large scale direct shear tests, with the square of thecorrelation coefficient being 0.96, thus yielding an increase of 120%over conventional geo-textiles.

Furthermore, the shear strength of the test embodiment equals or exceedstypical behavior of a conventional non-woven geo-textile when testedadjacent a non-smooth, or “textured” geo-membrane. Typical peak andlarge displacement friction angles between a conventional non-wovengeo-textile and a textured HDPE geo-membrane are 25.0 degrees. Theseresults are based upon non-woven needle punctured geo-textiles ofvarious weights, and on a database of 254 large scale direct sheartests, with the square of the correlation coefficient being 0.96 and17.0 degrees, and on non-woven needle punctured geo-textiles of variousweights, based on a database of 217 large scale direct shear tests, withthe square of the correlation coefficient being 0.95, respectively.”

Although the present invention has been described in connection withspecific forms and permutations, those skilled in the art willappreciate that various modifications and other than those discussedherein are within the scope and spirit of the invention. For example,equivalent elements may be substituted for those specified herein,certain features may be used independently of other features, andprocess steps may be modified, reversed or interposed, all withoutdeparting from the invention as recited herein and in the followingclaims.

1. A geo-textile having a first surface and a second surface, whereinsaid geo-textile further comprises a high-friction compound on at leasta portion of said first surface, such that said geo-textile possesses anincreased resistance to shear forces when said geo-textile is inadjacent contact with the surface of another layer.
 2. The geo-textileof claim 1, wherein said high-friction compound is provided on a firstarea portion of said first surface, and said first portion comprises apercentage of the surface area of said first surface.
 3. The geo-textileof claim 1, wherein said first area portion is at least 20% of saidsurface area of said first surface.
 4. The geo-textile of claim 1,wherein said wherein said first area portion is at least 45% of saidsurface area of said first surface.
 5. The geo-textile of claim 1,wherein said wherein said first area portion is at least 70% of saidsurface area of said first surface.
 6. The geo-textile of claim 1,wherein said wherein said first area portion is at least 95% of saidsurface area of said first surface.
 7. The geo-textile of claim 1,wherein said wherein said first area portion is 100% of said surfacearea of said first surface
 8. The geo-textile of claim 1, wherein saidhigh-friction compound comprises one or more from the group comprisingsilicone-based compounds, ethylene vinyl acetates (“EVA's”), styrenebutadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes,recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”),rubberized polyethylenes, ethylene propylene diene monomers, ethylenevinyl alcohol copolymers, polypropylenes, rubberized polypropylenes,polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins,silicone compounds, and compounds derived from recycled tires.
 9. Thegeo-textile of claim 1, wherein said geo-textile is one or more ofwoven, non-woven, needle-punched, and non-needle-punched.
 10. Thegeo-textile of claim 1, wherein said high-friction compound is adheredto said at last one of said surfaces by one or more of thermal bonding,one or more adhesives, laser welding, hot-melt bonding, ultrasound, andthe adhesive properties of said high-friction compound itself.
 11. Thegeo-textile of claim 10, wherein said thermal bonding of saidhigh-friction compound to said geo-textile is accomplished by A.effecting deposition of one or more of said high-friction compounds uponsaid first surface of said geo-textile, wherein said high-frictioncompound is deposited in the form of one or more of strands, fibers,beads, globules, flakes, powders, pellets, gels, liquids, crystals,films, matrices and sheets, and then B. supplying sufficient heat to oneor more of said high-friction compound and said geo-textile such thatsaid bonding is accomplished.
 12. The geo-textile of claim 1, whereinsaid high-friction compound is applied in one or more patterns.
 13. Thegeo-textile of claim 1, wherein said high-friction compound applied tosaid first surface has a first thickness, said thickness being measuredperpendicularly from the average mean surface of said geo-textile,wherein said first thickness is at least 0.1 millimeters.
 14. Thegeo-textile of claim 13, wherein said first thickness is at least 1.0millimeters.
 15. The geo-textile of claim 13, wherein said firstthickness is at least 2.0 millimeters.
 16. The geo-textile of claim 13,wherein said first thickness is at least 3.0 millimeters.
 17. Thegeo-textile of claim 12, wherein said one or more patterns are selectedfrom the group comprising, straight rows, curved rows, straight stripes,curved stripes, intermittent squares, intermittent circles, intermittenteccentric shapes, regular polygons, irregular polygons, checkerboards,lattices, wave patterns and repeating free-form or miscellaneousdesigns.
 18. The geo-textile of claim 1, wherein said high-frictioncompound is applied randomly.
 19. The geo-textile of claim 1, furthercomprising a high-friction compound provided on a second area portion ofsaid second surface, wherein said second portion comprises a percentageof the surface area of said second surface.
 20. The geo-textile of claim19, wherein said first area portion is at least 20% of said surface areaof said second surface.
 21. The geo-textile of claim 19, wherein saidwherein said first area portion is at least 45% of said surface area ofsaid second surface.
 22. The geo-textile of claim 19, wherein saidwherein said first area portion is at least 75% of said surface area ofsaid first surface.
 23. The geo-textile of claim 19, wherein saidwherein said first area portion is at least 95% of said surface area ofsaid second surface.
 24. The geo-textile of claim 19, wherein saidwherein said first area portion is 100% of said surface area of saidsecond surface.
 25. The geo-textile of claim 19, wherein saidhigh-friction compound comprises one or more from the group comprisingsilicone-based compounds, ethylene vinyl acetates (“EVA's”), styrenebutadiene rubbers, polyesters, ABS, polybutylenes, recycled latexes,recycled tire compounds, polyethylenes, polyvinyl acetates (“PVA's”),rubberized polyethylenes, ethylene propylene diene monomers, ethylenevinyl alcohol copolymers, polypropylenes, rubberized polypropylenes,polybutadienes, plasticized polyvinyl chlorides, thermoplastic olefins,silicone compounds, and compounds derived from recycled tires.
 26. Thegeo-textile of claim 1, wherein said high-friction compound isinterwoven among the fibers of said geo-textile during manufacture ofsaid geo-textile such that said high-friction compound is disposed on atleast a portion of said first surface.
 27. The geo-textile of claim 1,wherein said high-friction compound is provided in the form of fibers,beads, globules, flakes, powders, pellets, gels, liquids, crystals,films, matrices and strands, which are interwoven among the fibers ofsaid geo-textile during manufacture of said geo-textile such that saidhigh-friction compound is disposed on at least portions of both saidfirst and said second surfaces.
 28. The geo-textile of claim 1, whereinsaid adjacent surface of another layer is one or more from the groupcomprising geo-membranes, geo-grids, geo-textiles, paved surfaces,earthen surfaces, earth-aggregate surfaces, geo-nets, geo-mats andgeo-cells.
 29. The geo-textile of claim 1, wherein said high-frictioncompound comprises adhesive properties.
 30. The geo-textile of claim 29,wherein said high-friction compound is suitable for adhering saidgeo-textile to one or more of a geo-net, a geo-membrane, a geo-cell, avoid-maintaining core structure, and a second geo-textile.
 31. Thegeo-textile of claim 1, wherein said geo-textile is adapted and arrangedto comprise at least part of a removable or permanent cover for alandfill, artificial basin or other large structure.
 32. A method forforming a geo-textile, said geo-textile having an increased resistanceto horizontal shear forces with respect to one or more adjacentsurfaces, comprising the steps of A. providing a geo-textile, saidgeo-textile having a geo-textile first surface and a geo-textile secondsurface, B. effecting application of at least one high-friction compoundto said geo-textile first surface.
 33. The method of claim 32, whereinsaid application of said high-friction compound to said geo-textilefirst surface is effected by i) providing said high-friction compoundonto said first surface as said geo-textile is being formed, and thenii) applying sufficient heat to one or more of said high-frictioncompound and said geo-textile such that said high-friction compound andsaid geo-textile are bonded to one another.
 34. The method of claim 32,wherein said application of said high-friction compound to saidgeo-textile first surface is effected by providing said high-frictioncompound onto said first surface after said geo-textile is formed, andthen applying sufficient heat to one or more of said high-frictioncompound and said geo-textile such that said high-friction compound andsaid geo-textile are bonded to one another.
 35. The method of claim 32,wherein said sufficient heat is provided by one or more of flames,heated air, steam, infrared radiation, heated rollers, heated platens,microwaves, ultra-sound, the melt heat of said high-friction compound,and the heat of formation of said geo-textile.
 36. The method of claim32, wherein said application of said high-friction compound to saidgeo-textile first surface is effected by one or more of spraying, randomspattering, ultrasound, extrusion of said high-friction compound ontosaid first surface as said geo-textile is being formed, extrusion ofsaid high-friction compound onto said first surface after saidgeo-textile is formed, laser melting of said high-friction compound ontosaid first surface, and hot-melting of said high-friction compound ontosaid first surface.
 37. The method of claim 32, wherein said at leastone high-friction compound is provided in the form of one or more ofstrands, fibers, beads, globules, flakes, powders, pellets, gels,liquids, crystals, films, matrices and sheets.
 38. The method of claim32, wherein said high-friction compound comprises one or more from thegroup comprising silicone-based compounds, ethylene vinyl acetates(“EVA's”), styrene butadiene rubbers, polyesters, ABS, polybutylenes,recycled latexes, recycled tire compounds, polyethylenes, polyvinylacetates (“PVA's”), rubberized polyethylenes, ethylene propylene dienemonomers, ethylene vinyl alcohol copolymers, polypropylenes, rubberizedpolypropylenes, polybutadienes, plasticized polyvinyl chlorides,thermoplastic olefins, silicone compounds, and compounds derived fromrecycled tires.
 39. The method of claim 32, wherein said high-frictioncompound is provided on at least a first area portion of said firstsurface, and said first portion comprises a percentage of the surfacearea of said first surface.
 40. The method of claim 32, wherein, afterapplication and heating of said high-friction compound, said compoundcovers at least 20% of the surface area of said first surface of saidgeo-textile.
 41. The method of claim 32, wherein, after application andheating of said high-friction compound, said compound covers at least45% of the surface area of said first surface of said geo-textile. 42.The method of claim 32, wherein, after application and heating of saidhigh-friction compound, said compound covers at least 70% of the surfacearea of said first surface of said geo-textile.
 43. The method of claim32, wherein, after application and heating of said high-frictioncompound, said compound covers at least 95% of the surface area of saidfirst surface of said geo-textile.
 44. The method of claim 32, wherein,after application and heating of said high-friction compound, saidcompound covers 100% of the surface area of said first surface of saidgeo-textile.
 45. The method of claim 32, further comprising the step ofC. effecting application of said high-friction compound to saidgeo-textile second surface.
 46. The method of claim 45, wherein saidhigh-friction compound is provided on at least a second area portion ofsaid second surface, and said second portion comprises a percentage ofthe surface area of said second surface.
 47. The method of claim 45,wherein, after application and heating of said high-friction compound,said compound covers at least 20% of the surface area of said secondsurface of said geo-textile.
 48. The method of claim 45, wherein, afterapplication and heating of said high-friction compound, said compoundcovers at least 45% of the surface area of said second surface of saidgeo-textile.
 49. The method of claim 45, wherein, after application andheating of said high-friction compound, said compound covers at least70% of the surface area of said second surface of said geo-textile. 50.The method of claim 45, wherein, after application and heating of saidhigh-friction compound, said compound covers at least 95% of the surfacearea of said second surface of said geo-textile.
 51. The method of claim45, wherein, after application and heating of said high-frictioncompound, said compound covers 100% of the surface area of said secondsurface of said geo-textile.
 52. The geo-textile of claim 32, whereinsaid high-friction compound applied to said first surface has a firstthickness, said thickness being measured perpendicularly from theaverage mean surface of said geo-textile, wherein said first thicknessis at least 0.5 millimeters.
 53. The geo-textile of claim 32, whereinsaid first thickness is at least 1.0 millimeters.
 54. The geo-textile ofclaim 32, wherein said first thickness is at least 2.0 millimeters. 55.The geo-textile of claim 32 wherein said first thickness is at least 3.0millimeters.
 56. A method for increasing resistance to the undesirableeffects of horizontal shear forces between one or more geo-membranes,geo-textiles, geo-composites, geo-nets, geo-cells and void-maintaininglayers in a landfill installation, comprising the steps of A. providinga sheet-like high-friction geo-textile, said geo-textile having a firstsurface and a second surface, wherein said geo-textile comprises meansdisposed on at least said first surface of said geo-textile forincreasing the coefficient of friction between said geo-textile and anadjacent layer, and B. effecting disposition of said high-frictiongeo-textile adjacent to one or more of said geo-membranes, saidgeo-textiles, said geo-nets and said void-maintaining layers.
 57. Themethod of claim 56, wherein said disposition of said high-frictiongeo-textile is between a geo-membrane and a geo-grid.
 58. The method ofclaim 56, wherein said disposition of said high-friction geo-textile isbetween two geo-membranes.
 59. The method of claim 56, wherein saiddisposition of said high-friction geo-textile is between a geo-membraneand a second geo-textile.
 60. The method of claim 56, wherein saiddisposition of said high-friction geo-textile is between a geo-membraneand a void-maintaining layer.
 61. The method of claim 56, wherein saiddisposition of said high-friction geo-textile is on top of at least aportion of said landfill and underneath at least one of saidgeo-membranes, said geo-textiles, said geo-nets and saidvoid-maintaining layers.
 62. The method of claim 56, wherein said meansfor increasing the coefficient of friction between said geo-textile andan adjacent layer comprises at least one high-friction compound selectedfrom the group comprising silicone-based compounds, ethylene vinylacetates (“EVA's”), styrene butadiene rubbers, polyesters, ABS,polybutylenes, recycled latexes, recycled tire compounds, polyethylenes,polyvinyl acetates (“PVA's”), rubberized polyethylenes, ethylenepropylene diene monomers, ethylene vinyl alcohol copolymers,polypropylenes, rubberized polypropylenes, polybutadienes, plasticizedpolyvinyl chlorides, thermoplastic olefins, silicone compounds, andcompounds derived from recycled tires.
 63. The method of claim 56,wherein said high-friction geo-textile comprises means on both saidfirst and said second surfaces of said geo-textile for increasing thecoefficient of friction between said geo-textile and said adjacentlayers.
 64. The method of claim 56, wherein said high-friction compoundis provided on at least a first area portion of said first surface, andsaid first portion comprises a percentage of the surface area of saidfirst surface.
 65. The method of claim 56, wherein said first portion ofsaid high-friction compound covers at least 20% of the surface area ofsaid first surface.
 66. The method of claim 56, wherein said firstportion of said high-friction compound covers at least 60% of thesurface area of said first surface.
 67. The method of claim 56, whereinsaid first portion of said high-friction compound covers at least 95% ofthe surface area of said first surface.
 68. The method of claim 56,wherein said first portion of said high-friction compound covers 100% ofthe surface area of said first surface.
 69. The method of claim 56,wherein said high-friction compound applied to said first surface has afirst thickness, said thickness being measured perpendicularly from theaverage mean surface of said geo-textile, and wherein said firstthickness is at least 0.5 millimeters.
 70. The method of claim 56,wherein said first thickness is at least 1.0 millimeters.
 71. The methodof claim 56, wherein said first thickness is at least 2.0 millimeters.72. The method of claim 56, wherein said first thickness is at least 3.0millimeters.
 73. The method of claim 62, wherein said upper surface isdisposed for contacting one or more adjacent surfaces, and wherein saidhigh-friction compound is provided on at least a first area portion ofsaid upper surface, and said first portion comprises a percentage of thesurface area of said upper surface.
 74. The method of claim 63, whereinsaid first area portion of said high-friction compound covers at least20% of said upper surface area of said upper surface.
 75. The method ofclaim 63, wherein said first area portion of said high-friction compoundcovers at least 60% of said upper surface area of said upper surface.76. The method of claim 63, wherein said first area portion of saidhigh-friction compound covers at least 95% of said upper surface area ofsaid upper surface.
 77. The method of claim 63, wherein said first areaportion of said high-friction compound covers 100% of said upper surfacearea of said upper surface.